Retrofit adjustable eccentric front motorcycle axle

ABSTRACT

An adjustable axle assembly for the front fork of a motorcycle. In the preferred embodiment, the axle is received within an eccentric axle carrier which in turn is received within mounting holes in the front fork. The mounting holes utilize a pinch bolts as a clamping method to secure the eccentric axle carrier within the fork. In the preferred embodiment, loosening the pinch bolts allows the eccentric axle carrier to be rotated effectively moving the position of the wheel relative to the fork. Moving the wheel forward and backwards changes the trail characteristic of the motorcycle&#39;s geometry.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to motorcycles having two front fork tubes and more particularly, to front wheel position adjustment mechanisms for such motorcycles.

2. Description of Related Art

Motorcycles conventionally have a pair of front forks that support opposite ends of a front wheel axle. It is desirable to be able to adjust the position of the front wheel of the motorcycle with respect to the front forks, specifically the horizontal position of the front end (known as the front wheel trail), as this adjustment changes the steering characteristics of the motorcycle. With conventional motorcycles, this adjustment is not possible without changing the fork tubes or the fork tube carriers (also known as the triple clamps); an expensive and time consuming endeavor

Therefore, there exists a need in the art for a method and device for adjusting the front wheel trail of a motorcycle quickly and easily without the need to change parts.

SUMMARY OF THE INVENTION

The present invention provides an adjustable front wheel axle.

In a preferred embodiment of the present invention, an adjustable front axle assembly for a motorcycle includes a pair of fork tubes comprising an axle carrier housing, an axle carrier, a pair of wheel bearing carriers and a wheel comprising a pair of wheel bearings. The axle carrier housings are provided by the distal end of the fork tubes. Each axle carrier is received within the axle carrier housing and defines an eccentrically-disposed axle opening through which an axle extends. Each wheel bearing carrier is received by the wheel bearings on each side of the wheel. The axle extends through the axle carriers and wheel bearing carriers. The axle and axle carriers are coupled rotationally through a securing mechanism.

Rotation of the axle causes the wheel to move horizontally and vertically relative to the axle carrier housing. Accordingly, the position of the front wheel, both horizontally and vertically, relative to the rest of the motorcycle, may easily be adjusted. For most motorcycles, changing the horizontal position of the front wheel relative to the rest of the motorcycle has the most dramatic effect on how the motorcycle steers. Changing the vertical position of the front wheel relative to the rest of the motorcycle also has a small effect of the rake dimension of the motorcycle's steering geometry.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an adjustable front axle assembly

FIG. 2 is an exploded perspective view of an adjustable front axle assembly

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following is a detailed description of the preferred embodiment as it would appear on a modern motorcycle.

DESCRIPTION OF THE ELEMENTS

-   -   1) Front fork tubes     -   2) Front wheel     -   3) Front wheel bearings     -   4) Front wheel bearing locating tube     -   5) Wheel bearing carriers     -   6) Axle     -   7) Axle carrier     -   8) Axle carrier flange     -   9) Axle carrier housing     -   10) Axle flat     -   11) Axle flat to end     -   12) Axle carrier locating pin     -   13) Axle tapped hole     -   14) Wheel bearing inner race     -   15) Axle bolt     -   16) Axle carrier housing pinch bolts     -   17) Axle carrier housing slit

FIG. 1 illustrates the preferred embodiment. Referring to FIG. 1, the front wheel 2 is positioned between the front fork tubes 1. The wheel bearing carriers 5 locate into the wheel bearings 3. The axle carriers 7 locate into the axle carrier housings 9. The Axle 6 locates into and passes through the axle carriers 7 and wheel bearing carriers 5. Each of the axle carrier locating pins 10 mate flush to the surface of the axle flat 10 and axle flat to end 11 locating the axle carriers and axle rotationally.

The assembly is secured first by tightening the axle carrier housing pinch bolts 16. which secures one side of the axle carriers against horizontal and rotational movement. Second, on the same side, the axle bolt 15 is also tightened securing the axel 6 horizontally flush to the end of the axle carrier 7. Third, on the opposite side, the axle bolt 15 is tightened, applying a compression load between the axle carriers 7, wheel bearing carriers 5, wheel bearing inner race 14, the front wheel bearing locating tube 4, and the axle carrier flange 8. Finally, the opposite side axle carrier housing pinch bolts 16 are tightened, securing the entire structure.

The assembly is adjusted by loosening the axle carrier housing pinch bolts 16 on both axle carrier housings. To change the position of the front wheel 2 relative to the rest of the motorcycle, one of the axle bolts 15 is turned, which in turn rotates the axle 6 which in turn rotates both axle carriers 7.

FIG. 2 provides an exploded view of the preferred embodiment.

The description above is provided to illustrate generally the invention in terms of the preferred embodiment as is provided for the purposes of illustration, not limitation. One skilled in the art will appreciate that the invention anticipates other embodiments beyond the embodiment described above. Accordingly, the invention is limited only by the claims as set forth below. 

1) A front axle assembly for a motorcycle fork, comprising: an axle, an axle securing structure, two wheel bearing carriers, comprising an axle opening through which an axle extends, a wheel, said wheel comprising two wheel bearings positioned on each side of said wheel, said wheel bearings defining an opening through which a wheel bearing carrier extends, two axle carriers, said axle carriers defining an axle opening through which an axle extends, two fork tubes, each fork tube comprising an axle carrier housing, said axle carrier housing defining an opening through which an axle carrier extends, said axle carrier housing comprising an axle carrier housing securing structure, each of said axle carrier housings receiving each of said axle carriers, said wheel positioned between said fork tubes, said wheel bearing carriers positioned on each side of said wheel and extending into said wheel bearings, said axle extending through said axle carriers and said wheel. 2) A front axle assembly for a motorcycle fork, comprising: an axle, an axle securing structure, a plurality of wheel bearing carriers, each wheel bearing carrier comprising an axle opening through which an axle extends, a wheel, said wheel comprising two wheel bearings positioned on each side of said wheel, said wheel bearings defining an opening through which a wheel bearing carrier extends, a plurality of axle carriers, wherein each axle carriers defines an axle opening through which the axle extends, a plurality of fork tubes, each fork tube comprising an axle carrier housing, said axle carrier housing defining an opening through which an axle carrier extends, said axle carrier housing further comprising an axle carrier housing securing structure, wherein each of said axle carrier housings receives each of said axle carriers, said wheel are positioned between said fork tubes, said wheel bearing carriers are positioned on each side of said wheel and extending into said wheel bearings, and said axle extending through said axle carriers and said wheel, said axle opening offset with an axis of said axle carrier. 3) The front axle assembly for a motorcycle fork according to claim 2 wherein the number of wheel bearing carriers, axle carriers, and fork tubes, is two. 4) The front axle assembly according to claim 3, wherein said axle carriers are coupled rotationally to said axle through an axle carrier securing structure. 5) An axle carrier housing for securing an axle carrier having wheel bearings, an axle and a wheel comprising: an axle carrier housing securing structure, wherein axle carrier housing defines an opening through which the axle carrier extends, wherein axle carrier housings receives an axle carrier, wherein the wheel is positioned between fork tubes, wherein the wheel bearing carriers are positioned on each side of said wheel and extending into the wheel bearings, wherein the axle extends through said axle carriers and said wheel, wherein said axle opening is offset with an axis of said axle carrier. 